JPS62244897A - Lift table for unmanned dolly - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is an automatic guided vehicle (hereinafter referred to as AGV), in which a table on which cargo is placed can be lowered up and down on the AGV.
Regarding a lift table for V.

2. Description of the Related Art Conventional AGVs are used to transport parts and workpieces in unmanned factories, etc., and the AGV's cargo loading platform, that is, the table, is
It was fixed at V. However, when 80V is used for transportation on a machine assembly line or on a machine assembly line, for example, when used on an automobile assembly line, the workpiece placed on the AGV, such as the chassis of an automobile, is It is necessary to maintain the height position of the chassis, etc. at a position that makes it easier for workers to work, but in conventional automobile assembly lines, the height position of the shuttle line does not change compared to the shuttle line. The height of the worker's position was changed to make the work easier. For example, when attaching tires or the like to a vehicle chassis, a method has been used in which the position of the worker is lowered relative to the shuttle line to facilitate the work. However, this method has the drawback that the shuttle line, ie, the assembly line, is fixed, making it difficult to change this line. Therefore,
Even when using an AGV instead of a shuttle line, changing the height position of the worker to make it easier to work on the workpiece mounted on the AGV will cause problems in the AGV passage, that is, the assembly process. It becomes difficult to change the line. Therefore, in terms of assembly line changes and assembly work efficiency, it is better to hold the workpiece at a position where it is easier to alternate the height of the workpiece without changing the height position of the worker. It's convenient and efficient. For this reason, a method has been developed in which a table that moves up and down is provided in the AGV, the workpiece is placed on the table, and the workpiece is positioned at an appropriate work position by moving the table up and down. In this case, A.G.
As shown in FIG. 4, the table on the V is such that a pantograph 102 is installed on the V101, and a table 103 is placed on the pantograph 102 to move the table 103 up and down, and one link 104 of the pantograph 102 is attached at one end. is rotatably fixed to the vehicle body of AGVlol with a pin] 08, and the other end is provided with a roller 106 and touches the table 103.One end of the other link 105 is in contact with the vehicle body of AGVlol with a roller 107, and the other end is attached to the table 103. It is rotatably fixed with a pin 109.

Both links 104 and 105 are connected to pin 110 at the midpoint.
These links 104, 1
05. Another set of rollers 106 and 107 with a similar configuration is installed in the vertical direction of the paper in Figure 4 to form a pantograph, and the table is connected to the pin 109 at the fixing point of the link and the roller 10.
It is supported with 4 points by 6. A rod 111 is fixed between the pair of links 104, and the link 104 is rotatably pivoted to the rod 111. and,
A servo motor 112 is fixed to the lot 111. Further, a rod 11.3 is fixed to a pair of links 105, and the link 105 is rotatably pivoted to the link 113. A ball nut 114 is fixed to the link 113, and the ball nut 114 is It is screwed into a ball screw 115 fixed to the motor shaft of the servo motor 112. As a result, when the servo motor 112 is driven, the ball nut 114 moves left and right on the ball screw 115 in FIG.
The table 103 can be raised or lowered by expanding and contracting the distance between the rollers 106 and 107 and moving the rollers 106 and 107 from side to side in FIG.

Problems to be Solved by the Invention In the above-mentioned device in which the table 103 is raised and lowered by the pantograph 102, the table 103 is lowered,
The larger the distance between the pin 108 and the roller 107, the greater the horizontal force applied to the ball nut 114, which inevitably results in a large load on the servo motor. ,
The higher the table 103 rises, the slower the table 103 rises, resulting in the disadvantage that it is difficult to control.

Another disadvantage is that when the table 103 is raised, the rollers 106 supporting the table 103 move toward the center of the table 103, making the table 103 unstable.

Therefore, an object of the present invention is to maintain the load applied to the drive source constant regardless of the upper limit position of the table, and to make the relationship between the drive speed of the drive source and the upper limit and lowering speed of the table linear so that it is easy to control. Our objective is to provide a lift table for AGV.゛Means for Solving the Problems The present invention provides two pantograph mechanisms, one end of which is fixed to the front and rear of the vehicle body of an automatic guided vehicle, and one pantograph mechanism that is fixed to the other end of the two pantograph mechanisms. A table that can be raised and lowered by expanding and contracting the links, and a worm jack that is provided for each of the two pantograph mechanisms and whose screw moves up and down by the drive of the drive means are provided, and the screw of the worm jack rotates the pair of links of each of the pantographs. The above-mentioned problems were solved by providing a movable support.

Operation When the two worm jacks are operated synchronously by the above-mentioned driving means, the pair of links of each pantograph supported by the screws of each worm jack will move around the pin that pivots each link in accordance with the vertical movement of the screws. As a result, the table fixed to the top of the pantograph moves up and down. At this time, the amount of vertical movement of the screw of the worm jack and the amount of vertical movement of the table are in a proportional relationship, and the speed of the driving means for driving the worm jack and the speed of the vertical movement of the table are in a proportional relationship, and the vertical movement speed of the table and Positioning control becomes easier.

Embodiment FIG. 1 is a partially sectional side view of an embodiment of the present invention. 1
is the AGV main body, 2 is a table, 3a, 3b are pantographs installed at the front and rear of the AGV main body 1, 4a,
4b is an A-mu jack, and the screws 6a and 6b that move the worm jack up and down are a pair of links L3 of the pantograph.
, (in FIG. 1, the links of each pantograph are provided in another pair in the direction perpendicular to the plane of the paper) are rotatably supported in a pivot manner. 5a and 5b are servo motors as driving means for driving the A-musubi jacks 4a and 4b, respectively, and the motor shafts of the servo motors 5a and 5b are connected to the l-musubi jacks 4a and 4b by connecting means 7a and 7b. has been done.

FIG. 2 is a side view of one pantograph 3a and its drive mechanism, and FIG. 3 is a sectional view taken along line AA in FIG. 2.

The other pantograph 3b also has the same configuration as the pantograph 3a, and only the pantograph 3a will be described below.

The pantograph 3a of this embodiment has four links L1 to L4.
, and four links L1 corresponding to each link 1 to L4
-~L4'' are configured as a pair, and as shown in Fig. 3, these links L1~L4, Ll~L4~
are arranged in pairs in the direction perpendicular to the paper plane in FIGS. 1 and 2.

One end of the link 1 to L1 is connected to the AGV main body 1 with pin P1.
The other end is pivoted with pins P2 and P2".
Link L4. It is pivotally attached to one end of L4-. Also, link L4. The other end of L4- is pin P3. P3”
It is rotatably attached to the table 2 by a pin P3- (not shown).

On the other hand, the links L2, 12- have rollers Ba, Ba' rotatably supported at one end, and the rollers Ba, Ba'' are in contact with the bottom plate of the ΔGV main body 1 and support the pantograph 3a and the table 2.Link L2. The other end of L2- is pin P4.P4'' and link L3. They are each rotatably pivoted to one end of L3-. Also, link L3. At the other end of L3- there are rollers 9a, 9.
a'' (rollers 9a- not shown) are rotatably supported, and the table 2 is supported by the rollers 9a, 9a-.Also, links L1, Ll' and links L2, L2
- means pin P5. P5=, each intermediate point is rotatably pivoted, and link L3. L3-, link L4. L
Similarly, each intermediate point of 4- is connected to pin P6. P6= (
The pin P6- is rotatably attached by a pin P6- (not shown).

The worm jack 4a is disposed on the tip side of the AGV main body 1 with respect to the center of the pantograph 3a and at the midpoint between the links on both sides of the pantograph 3a.
A rod 8a is fixed to the tip of the screw 6a that moves up and down, and the end of the rod 8a is connected to the link L3. Pivot 1 to L3=
It is rotatably supported as a set. Worm jack 4a
is connected to the motor shaft of the servo motor 5a of the driving means via the connecting means 7a. ``Then, if we drive the servo motor 5a and move the screw 6a of the worm jack 4a upward in FIG. 2, for example, 1. (Hereinafter, only the operation of one link mechanism of the pantograph 3a will be explained) Pin P4. P6 is pushed upward to pin P/l.

Due to the rise of P6, pin P2. P5 also rises, and each sunk L
1 to L4 are in a state rising from the state shown in FIG. Meanwhile, roller 8a moves on the bottom plate of ΔGV main body 1, and roller 9
A supports the table 2 while moving on the underside of the table 2, and raises the table 2 horizontally. In addition,
A similar operation is performed in the other link mechanism of the pantograph 3a, and the table 2 is moved by the pantograph 3a to the pin P3. It is horizontally supported at four points by P3=, :ID9a, 9a-.

The above is the operation of the pantograph 3a, but the pantograph 3b also has a similar structure and action, and the servo motors 5a, 5b
When the pantographs 3a and 3b are driven synchronously, the pantographs 3a and 3b are driven synchronously, and the table 2 is supported by each pantograph 3a and 3b at 4 points, a total of 8 points, and moves up and down horizontally.

As described above, in the present invention, as shown in FIG.
Two pantographs are provided at the front and rear of the GV main body 1,
Since the table is moved up and down by the two pantographs, the support point for supporting table 2 is table 2.
Compared to the case where the table and pantograph are fixed at two points, and the other two points are supported by rollers on the car, compared to the case where the table and pantograph are fixed at two points and supported by one pantograph. However, when the table 2 is raised and lowered by two pantographs as in the present invention, the table 2 is fixed to the pantographs at four points at the four corners, so the table 2 becomes stable. Furthermore, as shown in FIG.
, 3b, the point of force applied to the pantographs 3a, 3b by the worm jacks 4a, 4b will be on the outside of the table 2, and the table 2 can be more stably held horizontally. can be retained.

Roughly speaking, the more the T-jacks 4a, 4b are placed outside, that is, the closer they are to the left side of the pin P4 in FIG.
Since the amount of vertical movement of the screws 6a and 6b is small, the table 2 can be moved downward significantly. However, although it is necessary to increase the output torque of the servo motors 5a, 5b that drive the outer jacks 4a, 4k), compared to the case where the table 2 is raised and lowered by a single pantograph, the drive! Since there are two servo motors for the tI source and the force is distributed, there is no need to increase the capacity of the servo motors 4a and 4b. Especially when driving a large load, if you try to drive it with one servo motor, that servo motor will be expensive, and it will be cheaper to drive it with two servo motors, so it is better to use a lift table for AGV that is cheaper overall. I can do it.

And the screws 6a, 6b of the worm jacks 4a, 4b.
Since the links of the pantographs 3a and 3b are directly driven in the vertical direction, the worm jack 5a,
Since the amount of movement of the table 2 and the amount of elevation of the table 2 are proportional to each other, it is easy to control the movement speed and positioning of the table, and since the pantographs 3a and 3b are driven via the worm jacks 4a and 4b, the pantograph The servo motors 5a and 5b can be driven with constant output torque regardless of the amount of expansion and contraction, and from this point of view as well, the table 2 can be easily controlled.

Furthermore, since the position of the servo motor is shifted from the center of the main body of the AGV and is placed outward, it has the advantage of being space-friendly for AGVs that have various ￥A units located at the center of the main body of the AG. quarrel.

Note that when driving two servo motors 5a, 5b synchronously, as is usually done in robots, each servo motor 5a, 5b controls its speed, In addition to feedback controlling the position, the numerical control device outputs pulse distribution to each servo motor based on a signal from the pulse encoder of one of the servo motors.

Further, in the above embodiment, two servo motors drive each pantograph, but one servo motor may drive a drive shaft, and the drive shaft may drive the worm jack of each pantograph. . Further, in the above embodiment, the worm jack 4a.

Pantograph 3a with screws 6a and 6b of 4b.

Although the point of action of 3b is set to link L3, other links may be used. For example, in FIG. 2, the screw 6a of the worm jack 4a may be applied to the link L2 or the link L1.

Effects of the Invention In the present invention, the pantographs provided at the front and rear of the AGV main body are each driven by two T-mushiretsu. Therefore, the table that moves up and down due to the expansion and contraction of the pantograph is driven by the four corners of the table. Since the points of force for raising and lowering the table are also at the four corner ends of the table, the table does not lift up even if a biased force is applied to the table and maintains a stable state. Since the two pantographs are supported by one V-type lever, the load of the table and the objects on the table are distributed and supported, so there is no need to use a large worm jack compared to when supporting with one pantograph.
It can be made cheaper.

Furthermore, since the pantograph is driven via the worm jack, the force applied to the drive source remains constant regardless of the expansion and contraction of the pantograph, making control extremely easy. Furthermore, since there is a proportional relationship between the elongation base of the screw of the worm jack and the elevation of the daple, the elevation speed and positioning of the table are facilitated, and the elevation control of the table from this point is facilitated.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view of an embodiment of the present invention, FIG. 2 is a side view of one pantograph and its drive mechanism, FIG. 3 is a sectional view of FIGS. FIG. 2 is a diagram illustrating the operating principle of a conventional AGV lift table in which the table is raised and lowered by one pantograph. 1... to 〇 V body, 2... table, 3a, 3b.
... Pantograph, 4a, 4b... Worm jack, 5a, 5b... Servo motor, 5a, 5b... Screw, L1 to L4. Ll-~L4-...Link, P1~
P6, Pi=, P2=, P/I=, P5”...pin, 8a, 8a, 9a...roller. Fig. 4

Claims (4)

[Claims] (1) Two pantograph mechanisms, one end of which is fixed to the front and rear of the vehicle body of the automatic guided vehicle, and a table that is fixed to the other end of the two pantograph mechanisms and can be raised and lowered by expanding and contracting the links of the two pantograph mechanisms. and a worm jack which is provided for each of the two pantograph mechanisms and whose screw moves up and down by the drive of the drive means, and a pair of links of each of the pantographs is rotatably supported by the screw of the worm jack. A lift table for automated guided vehicles. (2) The lift for an automatic guided vehicle according to claim 1, wherein each of the worm jacks is disposed on the vehicle body end side of the corresponding pantograph mechanism with respect to the vehicle body of the automatic guided vehicle. table. (3) The lift table for an automatic guided vehicle according to claim 1 or 2, wherein the drive means for each of the worm jacks is a servo motor provided for each worm jack. (4) The lift table for an automatic guided vehicle according to claim 1 or 2, wherein each of the worm jacks is driven by one servo motor and a drive shaft driven by the servo motor.